Although they may not be in common use just yet, there are already bike lights that automatically turn themselves on or off depending on ambient light levels. The SeeSense light, however, takes things a bit further. Not only does it respond to changes in lighting, but its makers claim that it can also determine the traffic situation in which the cyclist is riding, and adjust its output accordingly.
First of all, you may find yourself asking "What's wrong with a light that's on maximum brightness all the time?". According to SeeSense creator Philip McAleese, by reserving its brightest output only for situations where it's really needed, the SeeSense is able to extend its battery life – one charge of the integrated battery via a USB cable is said to be good for at least 12 hours of use, for a "typical commute."
Produced in waterproof head- and tail light models, the SeeSense contains a reverse-biased LED for measuring ambient light levels, along with an accelerometer. A microcontroller uses output from these sensors to determine factors such as cadence, uphill or downhill orientation, acceleration or braking, cornering lean, and yaw.
By feeding this data into models developed by McAleese, the microcontroller is further able to determine if the rider is doing things such as going through a road junction, navigating a roundabout, or moving through lanes of traffic. Using the LED, it is also able to detect not only when the Sun has gone down, but also if the cyclist has entered a tunnel, or if a car's headlights are approaching. In all cases, it responds by temporarily boosting the brightness and flashing rate of the light.
Additionally, the light is turned on and off using motion gestures – it has no power switch. If you do forget to turn it off, however, it will do so itself if it doesn't detect movement for over 10 minutes.
Fresnel lenses are used to create a beam that's visible from a wide range of angles. In its basic form, the headlight puts out 150 lumens at its highest setting, while the tail light manages 90. A planned Intense edition of the lights, however, will offer 200 and 120 lumens, respectively.
Philip and his wife/business partner Irene are currently raising production funds for SeeSense, on Kickstarter. A pledge of £60 (US$95) will get you a set of the basic lights, when and if the funding goal is met.
More information is available in the pitch video below.